Pressure sensors can be used to measure air speed, such as the air speed within a wind tunnel or the air speed of an aircraft. In some embodiments, several pressure sensors are fitted into recesses that are formed in the conical tip of a pressure probe. Typically, one sensor is facing axially forward at the apex of the conical tip, and several others (4-7 or so) are facing angularly outward on the conical sidewall of the tip. In this manner, directional components of the air speed can be measured.
Some pressure sensors are so-called time-variant or time-dependent sensors, which have a relatively faster response rate to fluctuations in pressure. Other pressure sensors are so-called steady-state or time-averaged sensors, which have a relatively slower response rate to fluctuations in pressure. Time-variant sensors must be located close to the measurement plane, and thus require a relatively larger volume and area near the measurement plane than steady-state sensors, which can be located some distance away from the measurement plane. Because air pressure can vary greatly from one position to the next, it is desirable for probes to be as small as possible, so that more measurements positions can exist within a given space, and so that the size of the probes themselves does not appreciable factor into the measurements.
Because two components of air speed (total pressure and flow angularity) tend to be of interest, two different probe types are typically used to take the two different measurements. For example, in the case of a wind tunnel, a first rake of probes with time-variant total pressure sensors might be set up for a set of experiments, and then a second rake of probes with steady-state flow angularity sensors might be set up for repeated runs of the experiments. On an airframe, two separate sets of probes might be set up to take measurements. The need to duplicate either experimental conditions or equipment is costly.
What is needed, therefore, is an air speed probe that tends to reduce issues such as those described above, at least in part.